Normal skin

Health and Safety. The dermal toxicology of alkaline solutions of thioglycolic acid has been reviewed extensively (63—65). The reagent has been found harmless to normal skin when used under conditions adopted for cold waving. Some irritation is observed on abraded skin but this appears to be associated with the alkaline component of the waving solution (65). Hand protection is recommended for the professional hairdressers who routinely handle these products. 

The immunorestorative potential of inosiplex has been evaluated in several clinical conditions, including post-surgical trauma, cancer patients with concurrent viral infections, and cancer patients receiving radiotherapy or chemotherapy. For example, most (84%) of the surgery patients remained immunologicaHy depressed, but 56% of the inosiplex-treated surgery patients had complete restoration of normal skin test reactivity (probability level < 0.0005). The use of inosiplex as an adjuvant to chemotherapy or radiotherapy appears to be valuable in the prophylaxis against opportunistic infections. 

Emulsion components enter the stratum corneum and other epidermal layers at different rates. Most of the water evaporates, and a residue of emulsifiers, Hpids, and other nonvolatile constituents remains on the skin. Some of these materials and other product ingredients may permeate the skin others remain on the surface. If the blend of nonvolatiles materially reduces the evaporative loss of water from the skin, known as the transepidermal water loss (TEWL), the film is identified as occlusive. AppHcation of a layer of petrolatum to normal skin can reduce the TEWL, which is normally about 4—8 g/(m h), by as much as 50 to 75% for several hours. The evaporated water is to a large extent trapped under the occlusive layer hydrating or moisturizing the dead cells of the stratum corneum. The flexibiHty of isolated stratum corneum is dependent on the presence of water dry stratum corneum is britde and difficult to stretch or bend. Thus, any increase in the water content of skin is beHeved to improve the skin quaHty. 

Skin Absorption. Normal skin absorbs HCN slowly. However, 2% HCN in air may cause poisoning in 3 min, 1% is dangerous in 10 min, and 0.05% may produce symptoms after 30 min, even though a gas mask or air mask is worn. Some areas of the body, such as the feet and mucous membranes, are more absorptive than others. Cuts and abrasions absorb cyanide rapidly, and 50 mg of HCN absorbed through the skin can be fatal. 

Epidermal Maturation and Wound Healing. All three PPAR isotypes are expressed during epidermal maturation each isotype has a specific pattern of expression in regard to development and the various layers of the epidermis. An important role for PPARS in the development and/or maintenance of normal skin health is indicated by the presence of defective wound healing in the PPARS-null mouse. 

Clinical loss of normal skin markings without scarring is reported after multiple sessions of traditional Baker s peels. 

Microbes responsible for skin infection often arise from the normal skin flora which includes Staph, aureus. In addition Strep, pyogenes, Ps. aeruginosa and anaerobic bacteria are other recognized pathogens. Vimses also affect the skin and mucosal surfaces, either as a result of generalized infection or localized disease as in the case of herpes simplex. The latter is amenable to antiviral therapy in selected patients, although for the majority of patients, vims infections of the skin are self-limiting. 

A 25-year-old Caucasian man presents with itchy lesions on his scalp, chest, back, elbows, and knees. He says these lesions started about a month ago, and seem to be spreading. Upon examination, the lesions are well-demarcated and are reddish-violet in color—easily distinguished from normal skin. They appeared raised and are covered with loose scales. Removing the scales caused pinpoints of bleeding to show up. 

The amounts of ointments and creams people apply are highly individualized. So are the techniques of application. Some patients vigorously rub semisolid formulations into the skin, while others just spread films until they are more or less uniform over the desired area. While pharmacokinetic assessments of a system s delivery attributes is ordinarily done using normal skin (in vitro) or on healthy volunteers (in vivo), the site of its clinical deployment is usually anything but normal. Rather, it is determined by the skin condition to be treated. Clearly, the manufacturer is without control over how a disease is expressed in a particular patient. For many diseases, disease manifestation can be anywhere on the body. Moreover, from individual to individual it varies in intensity and vastness. Thus, more area may be involved in one case than in another, and the barrier function of the skin may be more or less intact in any instance. This creates a set of imponderables with respect to delivery, efficacy, and safety. 

Normal skin appears to be devoid of PDGF receptors. Animal studies illustrate that rapid expression of both a and P receptor subunits is induced upon generation of an experimental wound (e.g. a surgical incision). Receptor expression is again switched off following re-epithelialization and complete healing of the wound. 

As a result of pathogenic T-cell production and activation, psoriatic epidermal cells proliferate at a rate sevenfold faster than normal epidermal cells. Epidermal proliferation is also elevated in apparently normal skin of psoriatic patients. 

The capacity of the photoactive material to penetrate into normal skin by percutaneous absorption as well as into skin altered by trauma, such as maceration, irritation, and sunburn. 

In an investigation of the water-soluble vitamins in human skin,71 it was found that 15 individuals showed relatively small ranges (less than 2-fold) for vitamin B12, folic acid, and biotin about 2-fold ranges in the cases of riboflavin, niacin, and thiamine about a 4-fold range in the case of ascorbic acid, and more than a 5-fold range in the case of pantothenic acid. In another study72 it was found that the total choline content of normal skin varied in four individuals over approximately a 10-fold range 127 to 1200 ig. per gm. The variation in the free choline in the same individuals was relatively small. 

Clinically unaffected skin in atopic dermatitis differs from normal skin the underlying barrier defect associated in more than 30% with filaggrin loss of function mutations first published in 2006 [4] leads to dry skin associated with a greater irritant skin response than in normal healthy skin. Microscopic studies revealed a sparse perivascular T cell infiltrate in unaffected atopic dermatitis skin that is not seen in normal healthy skin. 

Keratinocytes secrete a unique profile of chemo-kines and cytokines after exposure to proinflam-matory cytokines. Keratinocyte-derived thymic stromal lymphopoietin (TSLP) may be of particular importance in atopic dermatitis This protein is undetectable in normal skin or non-lesional skin in patients with atopic dermatitis, but is highly expressed in acute and chronic atopic dermatitis lesions [18]. TSLP instructs human dendritic cells to create a Th-2-permissive microenvironment by inducing the expression of OX40L which triggers the differentiation of inflammatory Th-2 cells [48]. 

Nickoloff, B. J. (1991) The human progenitor cell antigen (CD34) is localized on endothelial cells, dermal dendritic cells, and perifollicular cells in formalin-fixed normal skin, and on proliferating endothelial cells and stromal spindle-shaped. Arch. Dermatol. 127, 523-529. 

Sulfones, such as dapsone and sulfoxone (Diasone), are well absorbed orally and are widely distributed throughout body fluids and tissues. Peak concentrations of dapsone are reached within 1 to 3 hours of oral administration and have a half-life of 21 to 44 hours about 50% of administered dapsone is bound to serum proteins. The sulfones tend to remain in the skin, muscle, kidney, and liver up to 3 weeks after therapy is stopped. The concentration in inflamed skin is 10 to 15 times higher than that found in normal skin. The sulfones are retained in the circulation for a long time (12-35 days) because of hepatobiliary drug recirculation. The sulfones are acetylated in the liver, and 70 to 80% of drug is excreted in the urine as metabolites. 

Mechanism of Action An antibacterial agent that inhibits bacterial protein, RNA synthesis. Less effective on DNA synthesis. Nasal Eradicates nasal colonization of MRSA. Therapeutic Effect Prevents bacterial growth and replication. Bacteriostatic. Pharmacokinetics Metabolized in skin to inactive metabolite. Transported to skin surface removed by normal skin desquamation. 

Extravasation - norepinephrine SC Infiltrate area with a small amount (1 ml) of solution (made by diluting 5-10 mg in 10 ml of NS) within 12 hours of extravasation. Do not exceed 0.1 -0.2 mg/kg or 5 mg total. If dose is effective, normal skin color should return to the blanched area within 1 hour. 

For external use only avoid contact with face, eyes, genitals, mucous membranes, and normal skin surrounding warts... 

After oral administration, griseoftilvin is absorbed from the gastrointestinal tract and deposited in new epithelial cells that make up skin, hair, claws, and nails. The drug has a greater affinity for diseased skin than for normal skin. Increasing tlie surface area of the griseoftilvin particles and the dietary fat intake also increases drug absorption. 

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